BRENTWOOD (KDKA) — A man who runs a gun shop business out of his Brentwood home was badly injured this afternoon in a house explosion and two-alarm fire.

The damage along Tuxey Drive in Brentwood is obvious, but what caused it is still under investigation by the Allegheny County Fire Marshal and ATF.

KDKA’s Christine D’Antonio Reports:

“We arrived here for two reasons,” agent Joe Price, from the ATF, said. “One, obviously, because of the explosion. Our certified fire investigator will be working. Two, because of a licensed firearms dealer.”

Authorities say it was right around 5 p.m. when Frank Mihalovich was walking up the stairs from his basement when the explosion happened there.

Mihalovich, who lives there alone, was able to get out. But he was severely burned.

“It looked like the owner walking out to the ambulance, and then they just loaded him in,” Rich Verscharen, a neighbor said.

KDKA’s Brenda Waters Reports:

Brentwood fire crews and other departments arrived to the house, which was engulfed in flames.

“We did make entry real quick down, and real quick back out, because the fire was knocked down,” Brentwood Fire Chief Dan Niecgorski said. “That was after the fire was knocked down.”

When the back of the house collapsed crews rushed out. They’re all okay, but no will be able to go back in until it’s safe.

Another issue, the fact that the home also doubles as a licensed gun shop called Frank’s Guns.

ATF agents are handling that and the gas company was also on scene, making sure other homes don’t have to be evacuated.

KDKA’s Brenda Waters Reports:

Those who know Mihalovich says he’s well known in the community and that everyone’s pulling for his recovery.

“Knowing Frank for a number of years, I was certainly upset and disturbed by the occurrences here,” Brentwood mayor Dennis Troy said.